Transcript A CMOS-Control Rectifier for Discontinuous Conduction Mode

A CMOS-Control Rectifier for
Discontinuous Conduction Mode
Switching DC-DC Converters
ISSCC 2006 / SESSION 19 / ANALOG TECHNIQUES / 19.8
Tsz Yin Man, Philip K.T. Mok and Mansun Chan
Class presentation:
Davood Amerion
University of Tehran
28 December 2006
Preliminary
Power Supply topology
1- isolated
- Push-pull (Half/full bridge)
- Fly back
2- non isolated
- Buck converter
- Boost converter
- Buck-Boost converter
Boost Converter
[2]
Operating modes [2] :
- Discontinuous current mode
- Continuous current mode
MOTIVATION
• The power efficiency and inductor profile of switching dcdc converters are two of the most important issues in
modern battery powered mobile systems.
• Discontinuous-conduction mode (DCM) operation
enables both a reduction in the switching losses and the
use of a small inductor in the high switching frequencies
(10s to 100s of MHz).
• In this paper, a CMOS-Control Rectifier (CCR) is
proposed to simultaneously provide adaptive dead time
control and mV-range forward-voltage drop for sub-1V
highly efficient DCM switching dc-dc converters
employed in single cell battery-powered mobile systems.
CCR diagram [1]
Results [1]
• Technology 0.35μm 2-poly 4-metal CMOS technology.
• 1μH inductor.
• comparators in the proposed CCR facilitates nanosecond response
times, TON (~20ns) and TOFF (~60ns)
• the proposed CCR provides mV-range forward-voltage drop and the
conduction loss is significantly lower than silicon or Schottky diodes
• regulated output voltage of 2.5V with 100mA maximum output
current. The input voltage range is from 0.9 to 1.2V.
• a 4.7μF output capacitor and a 1μH inductor are used to facilitate
the application of the entire boost converter to modern pocket-size,
or even thumb-size, mobile systems.
• Maximum power efficiency of ~ 87% is achieved at 100mA output
current and 1.2V input voltage.
References:
•
[1] ISSCC 2006 / SESSION 19 / ANALOG TECHNIQUES / 19.8
Tsz Yin Man, Philip K.T. Mok and Mansun Chan
•
[2] Texas instrument: understanding boost power stage in switchmode power supply
application report, march 1999, SLVA061
Any question?